An ultrasound diagnostic apparatus and a method for operating the ultrasound diagnostic apparatus are provided, whereby a location of a needle or an insertion degree may be more conveniently and accurately determined when a user treats or diagnoses an object by inserting the needle into the object. The ultrasound diagnostic apparatus includes a first display device that displays a first ultrasound image and a second display device that operates as a battery, is wirelessly connected to a main body of the ultrasound diagnostic apparatus, and easily moves. The second display device displays an enlarged ultrasound image of a needle and is disposed near a patient.
